A new species of water strider discovered in Aichi

The research group comprising Nagasaki University Faculty of Education Associate Professor Shin-ya Oba, graduate student Naoki Hiraishi, and off-campus collaborators including Ryosuke Matsushima and Takafumi Morii, discovered a new species of water strider "Microvelia (Picaultia) pilosa" in Japan and published their results in Zoological Science.

As a type of water strider, M. (Picaultia) pilosa is small, with a body length of approximately 1-3 mm, and lives on the surface of water bodies such as paddy fields, reservoirs, and wetlands. To date, 19 species are known to exist in Japan. In this study, an examination of both the morphology and DNA of an unknown species found in Aichi Prefecture in 2019 showed that it was a new species. This species was named Microvelia (Picaultia) pilosa based on the morphological characteristic in which hair on the female was conspicuous. This is the first time in 57 years, since 1964, that a new species of Microvelia has been discovered in Japan.

The ecology of the water striders-including their habitat apart from those in Aichi Prefecture where these individuals were found is unknown; therefore, in the future, it will be necessary to elucidate their distribution and clarify their ecology and biology, including their feeding habits. In addition, because M. (Picaultia) pilosa is a small-sized species, it is possible that individuals from this species may have been misidentified as being from another species of Microvelia that has been described to date. It is thought that further investigation and review of specimens will be required in the future.